Occupational exposures in the food production industry have been associated with respiratory disease, including bronchiolitis obliterans (BO), an uncommon lung disease characterized by fixed airways obstruction. A review of common ingredients listed diacetyl among other flavorings and recent attention currently has been focused on diacetyl as the potential cause. Diacetyl is a component of natural butter, albeit a very small proportion. It is used to impart a butter flavor to food items, but is also used to create a number of other flavors including but not limited to strawberry, caramel, hazelnut and butterscotch. In 2007, the United Food and Commercial Workers Union nominated diacetyl for long-term inhalation testing by the NTP because of potential worker exposure via inhaltion. In addition to assessing the inhalation hazard from diacetyl, there is a need to characterize industry-wide worker exposures. NIOSH has identified critical research needs for workers exposed to diacetyl, including the measurement of workplace inhalation to diacetyl in food production industries. Respiratory issues have been annecdotally reported for cheese production (Wisconsin), yogurt (Ohio), and potato chip manufacturing. However, the potential for both exposure and disease in the flavored food production industry still remains largely unstudied. Walk through and exposure assessment surveys were completed at the five companies that agreed to participate in FY2009. Recruitment has continued with nine more companies agreeing to participate. Walk through surveys have been conducted at seven of the companies, with exposure assessment surveys being conducted at four of these. One additional exposure assessment survey is scheduled this fiscal year for a total of 10 participating facilities. These included two small scale dairies, three chocolate manufacturers, two potato chip manufacturers, one cereal manufacturer, one bakery and one flavor manufacturer. Evaluation of the collected data is ongoing and reports should be completed by FY11 to send to each participating company with their results. Preliminary results indicate that diacetyl is mostly non-detectable at the sites visited. Most of the sites in the survey were small to medium size, used small amounts of flavorings, or used no flavorings at all but produced or used products with naturally occurring diacetyl. Detailed analysis of the results will only begin after all the data has been collected and reported by the analytical laboratory. One company is installing engineering controls and expressed interest in a follow-up exposure assessment to evaluate the effectiveness of the engineering controls. If feasible, this follow-up survey may be scheduled in FY11.